7 12 CCMBERL.!ND. • [KELLY S -and far between in the Skiddaw' SlateR, and the t~earch for ·11.-0nnoviCIAN Fo~MA'l'JON (continued):. VOLCANIC them is only likely to be successful where the clea.vage is SERIES OF HORROWDA.LJo~ ( u Green Slates and Porphyries " undeveloped, or where it coincides with the bedding. The of Sedgwick).-All along their southern boundary the masses of fallen stones or ~crees found on the mountain Skiddaw Slates pass under a great series of beds of yoloanic sides should be diligently examined. ash and breccia, alternating with sheets of Java, and the whole traversed by dykes and other masses of igneous . Numerous species of graptolites have been found ir~ the rock. It is most remarkable that aloiJg all this !me of juner higher or upper part of the Skiddaw slates, with brachio­ tion there runs a zigzag fault or dislooation, so that the pods, trilobites, and several plant remains; worm-tracks nature of an undisturbed passage from the one formation to :and worm-burrows are not very rarf'. Altogether these .... !!: the other is nowhere distinctly fossils would seem to indicate that the Upper Skiddaw Slate.~ 0 cl seen, Elsewhere. however, ltt are of about the same age as the Arl'nig Beds and Lower 1""'4 ~ 'C .q ·a~ Black Combe. and on EycoU Hill, Llandeilo strab of Walesr which are members, or Rub­ ,.~ . 1--.J< 0~ divisions, of the great OrmovmrAN GRoUP of stratified rocks ; ,. ·H, ~ w and above the Hollows Farm, they must have originally been deposited as beds of mud, :: .. H .o "' near Grange, in Borrowdale, beds ,.._ . :· r-...j• t>iJ of slate and volC'anic ash are seen -$and. or grit, on t.he bottom of a rather shallow ~ea. Their ' .. H-e '8: .... "' "' o to alternate at 'the junctiou, and strike, or line of extension, is from ll<>rth-east to south­ . ... ~--~-· • • .. •.. • tl-;1 § there is no doubt but that the west, and their dip, though they undulate greatly, is very ' .. j!:~~ generally to the south-east. Hut in the Lower Skiddaw t. o 9 higher 6eries rests conformably .Slates we rind near the top (at Harf) some graptolites, H fd . :; "" § on the lower one . which indicate that the black argillaeeous slates which ' !:= ] The Borrowdale beds are .contain them are of the , a me geological age as the Tremadoc . :: finely seen in the valley from ~ "' which they are named ; they oc- Slates of North Wales, and others which may even belong M os " ;t; -to the Lingula Flags of the same locality. But these 00 p cupy all the south and south-east Tremadocs and Lingula Flags .belong to the great CAM­ ::;;~ [;>;.,e11 ....., of Cumberland, from the west BRlAN FORMATION (upper part) : lastly, beneath all these Jco .g ""''1i side of Ullswater toDerwentwater, fossiliferous layers we still have left a great thickness of :5:1 ~ Ennerdale Water, Wastwater, Skiddaw Slates (much like the Manx Slates of the Isle of &:i ,; Harter Fell, W oodend Dud don Man) which have hitherto yielded no traces of life (no M ~ t;.5 Hall, &a., and extend over the fossils), but which may possibly be of Lower Cambrian age. ~....; border southwards into W estmor­ P:: t land ; their principal heights are-: Thus the Skiddaw Slates must certainly be divided into an • Cll .:::. Upper and a Lower division; but exactly where the line of ~ ~.... Harter Fell, 2, 141 feet; t:lcaw Fell separation should be drawn is a matter requiring more re­ ....a""' .a j" Pik es, 3,229 feet ; Great Gable, t~earch. M,....~.,; 2,949 feet. ; High Stile, ~643 feet; .... ., .s ~ ~ Causey Pike, 2.082 fPet; Glara­ In the neighbourhood of the igneous rocks the Skiddaw ~ ~ ~ mara, 2,56o feet; Ullscarf, 2,370 Slates have been metamorphosed, being converted first .g ~ 'i feet ; and Great Dodd,-2,807 feet. into chiastolite slate, then (as we get nearer to the granite) into spotted or Andalusite Schist, and finally (when in .S~.a The total thickness of'the Vdl­ .actual contact with the igneous rock) into mica-schist; o:. ~ -~ canic Sf'ries is about 12,oo0 feet ; at some points, as in Skiddaw Forest, where the slaty beds . ~ ~ ~ formerly the beds must have 'i ~ ": o extended right over the surface are obviously much altered, although no igneous rocks are ~ {/) Q;) •1""4 seen anywhere near on the surface, yet doubtless granitic ~ ~ area now occupied by the Skid- e~~ ~ masses exist beneath at no great depth. • ...... 0 daw Slates, for we find them !A~ resting on the latter, uot only on The following fOb-divisions of the Skiddaw Slates have o Fll"' the south, as already described, been indicated by• Mr. J. C. Ward:- ~ i!= • '!ii but also on the north at Caldbeck 6. Passage beds to Volcanic Series above. .5:: ~ ~ Fells, Eycott Hill, Ulldale and 5· Black slates of Skiddaw. ~ 1l ~ Sunderland. 4· Gritty beds of Gatesgarth (Buttermere), Lutter­ o : ~ As to the mode of format ion of barrow. 'l'ongue Beck, Skiddaw, Watch Hill and """j ~ the Volcanic Series, it is plain Great Cockup. ~ .., tl that towards the end of the Skid­ 3· Dark slates. ·~ . S daw Slate period submarine vol­ -c 2. Sandstone series of Grassmoor and Whiteside. ~! canoes burst into action, and for ~o ~ a time beds of lava and ash were I. Dark slates of Kirk Stile, betwten Loweswater and Crummock. -; ~ og deposited on the sea-bottom ~:; p. alternately with layers of mud A bed of grit in No. 4 Mr. Ward considers like one (the ~ ~ - and sand; but elevation of the "'Gart.h Grit") which occurs at the base of the Arenig ~ ~-~ sea-floor taking place the whole .Slates of Wales; if this be 110 then the lower strata may be ·a~ area became land, and all .the -of Cambrian age. No. 2 representing the Lingula Flags, ~ ~·a superincumbent. beds composing .and No. 3 the Tremadoe Slates; the finding of more fossils .::: ';;"' the middle and upper parts of in these lower beds is necessary to decide <this question. § -~ -E the Volcanic Series conbist of 'The best existing collections of the Skiddaw Slate fossils ~ ~ J31> similar volC'anic lllatter which are in the museums at Cambridge and at Keswiek ; many w c.> ll fell uvon and around the volcanic .o'f the best specimens were collected by the )ate Mr. W. K. ... ·s; cones. One of the main centres Dover, of Keswick. -..:] i of eruption is probably repre­ ~ .£ ~ .., sented by the round boss of in tru­ Some beds of the Skiddaw Slates have been worked for -e~ Q) ~ sive igne~ms rock ( do-lerite ), which fllate pencils at Keswick, but the chief economic value of the :;3 w forms Castle Head, near Keswick, rocks lies in the numerous mineral vems by which they are M and from "hich probably flowed traversed; and which are generally also lines of fault, where the lavas of Wallow Crag. All trace of the actual cones lracture of the rocks has taken place, the cracks or fissures and craters of the old volcanoes is of course gone long since ; thus produced having been filled by n1inerals deposited by they have all been denuded, and swept away by the SCfl, heated water traversing the ~trat.a. or by vapours rising up by rain, and rivers, &c . .; wha-t 'lll"e now see for instance ati from below. · Castle Head is the stump or plug of the old volcano, rock In 1908 of zinc ore 2,746 tons were obtaine;:J near Keswick. matter (diabase) which solidified, perhaps, thousands of feet below the actual summit. Iron ore {a red hrematite) has been worked in the hills between ButtermerP- and Ennerdale Lake, and in Eskdale. A strong proof of the subaerial erigin of the Borrowdale ln fol'Uler times copper was 'largely worked at Newlands, Volcanic ~eries is the entire absence of fossils ;, such a west of Derwentwater. thickness of strata could scarcely accumnlate in the sea. with­ out enclosing some evidences of the life of the period. As a general rule the Copper Lodes run east and west, and the Lead and Iron Lodes north and !lOuth ; the former A fine section of these beds is exposed on tbe &ides of -appeal" ~ be the older, being frequently displaced or shifted Falcon Crag, Brown Knotts and Bleaberry Fells, two miles by the latter. south of Keswick. 'fhe strike is the same as that- {)f the The mountains formed of ~kiddaw Slates have soft out- underlying Skiddaw Slates, ,-iz. from north-east tu south· lines and smooth grassy slopes, exeept where intrusive west. igneous ntasses oecur; thus the doleritic boss of Ca!itle The following table uy Mr. J. C. W~o.l'd shows the general Head. near Keswick, stands out aw a bold crag above the succession of the volcanic beds, the _oldest beiJJ.g at the surrounding and softer slates, and the igneous dyke forming base:.- Friar's Crag, overlooking Derwentwater, serves as a strong J 9- Bedded~ mostly fine flinty ash, of Great .End. Esk}'ike lake-wall pro.tecting the softer rock.behind it. J and Alien Crags. _ .